1. Field of the Invention
The invention relates to slide fastener stringers and to their method and apparatus of manufacture wherein each stringer has head portions of a continuous filament coupling element extending from slots in a folded edge of a support member.
2. Description of the Prior Art
The prior art, as exemplified in U.S. Pat. Nos. 1,557,303; 1,933,390; 1,937,297, and 3,430,304 and British patent specification No. 1,161,016, contains a number of slide fasteners having continuous chains of coupling elements or the like secured within a fold of a carrier tape wherein the head portions of the coupling elements extend from slots across the folded edge of a leather or fabric strip or extend from apertures formed by weft threads and a wide spacing between warp threads of woven carrier tape. The prior art slots and apertures extend perpendicular to the folded edge of the carrier tape; such perpendicular slots in slide fasteners employing spiral or coil type fastening elements result in excessive distortion and relatively inferior support for the spiral coupling elements.